lib/standard/string: C implementation basics for UTF-8 String encoding as Standard

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/standard/string: Added function copy_to on index.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/standard/string: Adapted * for Unicode Strings.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/standard/string: Added routine to compute the code_point of a UnicodeCharacter.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/standard/string: UnicodeChars can now be tested for canonical equivalence.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
lib/standard/string: Reversed adapted for UTF-8.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>